1. Field of the Invention
The present invention relates to a manufacturing method of imprinting template and the imprinting template thus manufactured, and particularly to a manufacturing method of imprinting template using a semiconductor manufacturing process and the imprinting template thus manufactured.
2. Description of the Prior Art
Nanoimprint techniques are directed to microlithography techniques to form features having a line width below 100 nm. The various nanoimprint techniques can be categorized into three main categories: nanoimprint lithography (NIL), step and flash imprinting lithography (SFIL), and soft lithography. In the nanoimprint lithography technique, a large area of nano structure can be imprinted by a hot press method. In the step and flash imprinting lithography technique, the nano pattern can be formed by exposure with UV light at room temperature. In the soft lithography technique, the concepts of Top-Down and Bottom-Up are combined and a pattern with a curvature can be transferred using a flexible template. An imprinting template is needed in the nanoimprint techniques. Conventional imprinting templates may be made by direct writing with electron beam (or E-beam), X-ray lithography, or ion beam lithography. However, a pattern with a high aspect ratio (deep profile) is not easily obtained using aforesaid techniques; moreover when a pattern with a high aspect ratio is intended to obtain, the pitch of the features have to be increased. Furthermore, using e-beam to directly write a pattern on an imprinting template is very time-consuming and costly. Recently, it has been known that the pitch of the pattern can be attained from 200 to 410 nm, after development inspect critical dimension (ADICD) is 130 to 250 nm, and the depth is 6000 to 7000 angstroms.
In other respect, in recent years, there have been some practices of LED devices using a photonic crystal structure. For increasing the light emission from the axial direction, a surface roughening process is performed in an LED manufacturing process; however, since the roughened surface situation is not controllable, dissipation of some emitted light still cannot be avoided and the efficiency of light emitting is damaged. Accordingly, the photonic crystal structure is used to increase light-emitting efficiency. A photonic crystal is broadly defined as a material having optic properties periodically changed. For example, small balls having a low refractive index are periodically arranged in a background material having a high refractive index, similar to atoms forming a solid crystal in a regularly and periodically arranged structure. FIG. 1 shows a schematic cross sectional view illustrating a conventional LED device having a photonic crystal structure located on the surface. The LED device comprises a substrate 10, cladding layers 12 and 14, and an active layer 16. The upper surface of the cladding layer 14 has a photonic crystal structure.
Generally, the manufacturing approach for such kind of photonic crystal may simply use, for example, a machinery drilling. While considering the frequency band of visible light or near infrared ray, a nanoscaled fabricating process is used. There are two main methods for making the nanoscaled photonic crystals. One utilizes the self-assembly of colloidal particles, and another one utilizes the lithography combined with etching process to make a lithographic mask and etch the substrate surface through the lithographic mask to form the photonic crystal.
Therefore, there is still a need for methods of manufacturing nanoscaled imprinting templates for making imprinted articles in sub-micro or nano dimension conveniently and economically.